TG100 Flashcards
where do many of the failures in radiation oncology occur?
errors in workflow and process
what is TG100?
application of risk analysis methods to radiation therapy quality management
FMEA
failure modes and effects analysis
issue with work practises in individual clinics
very variable
not like linacs where there are some standard designs and you can prescribe QA
-have to analyze processes and develop clinic and site specific quality management programs that affect work practises in individual clinics
techniques used in TG100
process mapping
FMEA
fault tree analysis
3 things included in TG100
(1) the rationale for prospective risk analysis; (2) how to perform process- and clinic-specific risk analysis and quality management program formulation; and (3) a detailed sample application of the method applied to a generic IMRT process
does TG100 recommend making sudden big changes to workflow after the analysis?
No, discuss with experts and team first
make sure still compliant with regulations
4 recommendations of TG100
- Don’t make sudden large changes to workflow due to results of analysis
- Start with a small project
- Use redundancy
- Quality department at the clinic can likely provide help
what happens to physics resource demands as methods become more intensive and complex?
the demand grows
-ex IMRT and OBI QA
What is linked to serious errors in some radiation therapy accidents?
mental and physical overload
what is not meeting the desired level of quality?
failure
definition of quality
Those features which meet the needs of the patient,including rational medical, psychological, and eco-nomic goals while also taking into account the profes-sional and economic needs of the caregivers and theinstitution.
•A clinical process that is designed to realize cancer treat-ments that conform with nationally accepted standardsof practice and specifications; and
•Freedom from errors and mistakes
define error
failures consisting of acts, either of commission(doing something that should not have been done)or omission (not doing something that should have been done), that incorrectly execute the intended action required by the process
define mistakes
failures due to incorrect intentions or plans, such that even if executed as intended would not achieve the goal
define violations
failures due to intentionally not followingproper procedures, either as shortcuts with the intentionof achieving the correct goal or sabotage
define event
the entire scenario, including the failure it-self and its propagation through the clinical pro-cess, resulting in a patient treatment of diminished quality
define near-event
a situation resulting from a failure that would have compromised quality of the patient’s treat-ment had it not been detected and corrected. Also known as close call, near miss, and good catch
types of failures
human
equipment
organizational or design (latent)
what is essential performance
defined by the International Electrotechnical Commission (IEC) as the performance neces-sary to achieve freedom from unacceptable risk
risk mangement
systematic application of management policies, procedures, and practices to the tasks of analyzing,evaluating, and controlling risk
risk assessment
considers the way in which the quality of treatments can fail to achieve the desired goals
4 components of quality management
quality planning
quality control
quality assurance
quality improvement
difference between QC and QA
QC maintains integrity of process
QA provides confidence that the output of the process is correct
i.e. QC is about input and QA about outpout
for example, QC failure would be not realizing a system is using the wrong calculation algorithm. QA failure would be not seeing that the calculated result is incorrect
QC usually requires more resources than QA
RCA
root cause analysis
reactive approach to safety (once an incident occured or almost occurred)
-focuses on systems and processes rather than individual blame
safety barriers
critical control points
any process steps whose primary function is to prevent errors or mistakes from occurring or propagating through the radiotherapy workflow
prospective risk analysis
goal is to identify risky process steps before a failure happens
overview of FMEA
it moves through the process and considers, for each step, what could fail, how it could fail, what is the likelihood of failure, what is the likelihood that a failure would not be detected, and what the effects of failure would be. The overall risk of each identified failure mode is then scored, so that these failure modes can be prioritized
overview of fault tree analysis
evaluates the propagation of failures
order of steps in TG 100
- process mapping
- FMEA assess all potential risks
- FTA evaluates propagation of failures
- QM program is developed based on how to best avoid the faults and risks identified
the team for TG-100
multi-disciplinary
three parameters in FMEA
- O(occurrence) describes the likelihood that a particular cause for the specified failure mode exists.
- S(severity) describes the severity of the effect on the final process outcome resulting from the failure mode if it is not detected or corrected.
- D(lack of detectability) describes the likelihood that the failure will not be detected in time to prevent an event.
they range from 1-10
While past experience with QC or patient outcome studies might be available to guide the choice of the value for D, its selection will rely largely on expert opinion
RPN
Risk priority number in FMEA
RPN = OSD
ranges of OSD
Oranges from 1 (failure unlikely,<0.01%) to 10 (failure likelihood is substantial, more than 5% of the time).
•S ranges from 1 (no danger, minimal disturbance of clinical routine) to 10 (catastrophic, whether from a single event or accumulated events)
•D ranges from 1 (very detectable: 0.01% or fewer of the events go undetected throughout treatment) to 10 (very hard to detect,>20% of the failures persist through the treatment course).
as S increases, what happens to D?
typically more severe issues (such as horrid coverage) become more likely to be detected)
ranking of QM tools from most effective to least effective
most effective: forcing functions and constraints (interlocks)
- automation
- protocols (i.e. checklists)
- independent double-checks and other redundancies
- rules and policies
- education
common themes on safety and quality in RO
training, documen-tation, communication, and both reactive and prospective approaches to error management
issue with estimating detection rate
few studies document this
dominant cause of failure
human failure
highest ranking hazard in TG100 IMRT example
incorrect interpretation of a pre-treatment disgnostic image for defining the GTV
-peer review is most effective QM step
2nd highest ranked hazard was bad delineation of GTV (similar issue)
key quality compoennets identified
-Standardized procedures.
•Adequate training of staff.
•Clear lines of communication among staff.
-Maintenance of hardware and software resources.
•Adequate staff, physical and computer resources.
